Check agent logs in /var/log/cloudera-scm-agent/ on the host being added (some of the logs can be found in the installation details).

Applies To

Cloudera Manager (All Versions)

Cause

This type of error can be caused by several factors, but they all come down to the client nodes being able to correctly communicate back to the Cloudera Manager server over the network.

Potential root causes of this error:

Your client machines do not have their IP addresses configured properly.

Firewalls and/or iptables could be blocking network traffic.

DNS is misconfigured

Troubleshooting Steps

1. IP Address misconfiguration:

Use "ifconfig -a" to see a listing of your network interfaces, your main network interface is probably something like "eth0". Assure that it has a real IP address, not the loopback address (127.0.0.1) assigned to it. Run the "hostname -f" command to find out what hostname your local machine is using for itself, then run "nslookup <hostname>" against that hostname (or "dig <hostname>" for more options) to see what IP address it is resolving to. If DNS does not return an IP address for your host, then the configuration will be strictly controlled by /etc/hosts. Look in that file to see what IP address you are assigning to your host.

2. Firewalls or iptables: either disable them or assure they are allowing the correct ports to pass through. Follow you company policies to decide which path if best for you.

$ sudo chkconfig iptables --list

iptables 0:off 1:off 2:off 3:off 4:off 5:off 6:off

$ sudo ufw disable

3. If "nslookup <hostname>" (where <hostname> is the name of your Cloudera Manager server) does not return the correct IP address, then you have a misconfigured DNS, contact your network admin.

When it's all said and done, all machines in your cluster need to be able to resolve each other's hostnames and IP addresses as well as connect to each other on the specific network ports mentioned in the error message. Assure that /etc/hosts or DNS are configured properly so that your hosts can resolve each other and that each local machine is binding it's hadoop services to a real network IP instead of the loopback address.

If all that is correct and you still cannot connect, check to make sure firewalls or other services are not blocking the traffic.

I have the same issue and checked everything suggested by Clint. Firewall is disabled, Manager is listening on 8182. hostsa are able to resolve names to correct IP. Not sure what is missing. I am installling CDH-5.13.1-1.cdh5.13.1.p0.2 and I am trying to use "Single User Mode", could that be a problem ?

I'm having the same issue's and need some help to get through this....

On a RHEL7.3 installed in a VM (VirtualBox) i'm trying to install a single node cluster using cloudera manager (Cloudera Express 5.14.1). I get stuck when adding a single agent node (on localhost that is).

Ensure that ports 9000 and 9001 are not in use on the host being added.

Check agent logs in /var/log/cloudera-scm-agent/ on the host being added. (Some of the logs can be found in the installation details).

If Use TLS Encryption for Agents is enabled in Cloudera Manager (Administration -> Settings -> Security), ensure that /etc/cloudera-scm-agent/config.ini has use_tls=1 on the host being added. Restart the corresponding agent and click the Retry link here.

I've checked, fixed, rechecked:

- no firewall is enabled

- selinux is disabled

- ipv6 is disabled

- ntp is setup

I have stopped, wiped, restarted the installation many times now but i always get stuck at this point.

I have extended my hosts files with:

10.0.2.15 my-host.local my-host

But i have found that when i try to aff my-host in the wizard it first seems to setup the agent at my-host.local @ 10.0.2.15, but then when i hit the error, if i open: http://localhost:7180/cmf/hardware/hosts it always shows up as localhost4.localdomain4. Then also the most odd thing is that in the hosts overview there is a Last Heartbeat column that actually shows that the heartbeat is working: it's like 4.26s, then when reloading it's 1,5s, etc....

I have checked both the cloudera-scm-server and cloudera-scm-agent logs but did not find any usefull things.

On agent edit /etc/cloudera-scm-agent/config.ini to point to Cloudera manager (if nedded)

# Hostname of the CM server.

server_host=nodexxxx

Start Agent

# service cloudera-scm-agent start

# chkconfig cloudera-scm-agent on

Login to Cloudera manager and while adding host, insteading of selecting new host from the list, look for "Currently Managed Hosts(1)" link on the top of the screen. Click on the link and select the host from list.